I needed an inexpensive and simple battery pack to power a 10 foot piece of EL (electroluminescent) wire, and this work perfectly. You have multiple lighting options (steady vs. flashing), which can be selected using a single push-button on the battery case. The output was more than enough to power my length of EL wire, and worked perfectly as a clip-on battery pack.Construction of the battery pack is simple and cheap, but that's what I expected and planned for when purchasing it. It's held up well, and thanks to the basic design, hasn't had any issues. It's taken a few lumps (dropped a few times, etc.) and continued to function without problem. Great, portable way to light your EL wire/project.